A “holiday drive” from here to Dulles set a family record — 4 1/2 hours. Interstates 81 and 66 can really take a toll when they jam.

We set out Friday eve before Christmas to catch a flight to Texas, a visit with the extended clan. Bad timing, we learned.

From a long bumper-to-bumper tie-up we took away lessons, based on observations of others in the backup, and from our own questions about standstill traffic etiquette, which our backseat student driver answered in an Ask-Google-athon.

Nationwide, Friday night ranks as the worst in the country for traffic delays in and around major metro areas. D.C.’s I-95 rates as the worst for commuters. A few spots behind, the Beltway’s congestion follows in the countdown of America’s 25 terrible rush-hour drives.

We hit the road after quitting time, far from those maddening crowds. Alas, we were trapped with hundreds of others near Strasburg, where semis had piled up. Crews had hours of work to clear the mess.

Next time we’ll make a Thursday or Friday morning departure from home. We’ve also got to get in the habit of turning on the traffic-spotting app before leaving our driveway.

Had we done so we might have skipped over the Blue Ridge to Charlottesville, then made our way north on 29. Or, swung east on highway 33 out of Harrisonburg. Either might have shaved a couple of hours off the trek, and lowered our frustration.

Other travelers trapped in the standstill also got us thinking. Mostly: “What are they thinking?!”

One driver had to answer nature’s call. We’d been stuck for more than an hour at that point, so I could sympathize. A long line of traffic ahead hadn’t moved, so he darted from his vehicle to climb down a steep embankment, disappearing courteously into deep shadows of the median’s gully.

A class act, I thought, compared to the driver one lane over.

She thrust a phone out of the window to video tape his quick detour and return from the trenches. Class act, that. Her music selection, blaring pop, also leaked into nearby vehicles.

And one of her headlights had burned out. Typical of a dim bulb.

Once clear of traffic, ages later, we made a McStop, but not for the food. If you’re ever in a traffic bind, there are videos out there with tips for dealing with bodily functions if you can’t get to the arches. We’re an inventive species.

Weaving between lanes to “get ahead” is another dumb move, according to the research. Charging down the emergency lane at intervals is dumber.

Dumbest: Twice, tow trucks, the models that haul off crippled18-wheelers, had to lay on their horns to get drivers to pull back into the traffic lane. At one exit a motorist pulled perpendicularly into the stalled line of vehicles trying to get off the interstate. Cars whizzed by in the passing lane just feet away. Amazing dumbness.

Eventually I learned, however, that inching along behind a toxin spewing-pickup justifies lane changes. Clouds of black diesel poured from the over-sized tail pipe of the truck we followed for too many miles. He liked to rev the engine, smoke signaling his density.

I finally kept a three-car gap between us. “Spewy" eventually ran out of patience, and darted off to try a cross-country approach to his destination.

Riding our back bumper became a pastime for another impatient driver. She must have seen the multi-car gap in front of us, the smoke-free zone, and coveted the spot.

At its peak, my road rage turned to all of the drivers who kept their engines running, even during 15-minute episodes of zero forward progress in balmy weather! (Compared with this past week’s temps, that is.) The air pollution, the waste, the weeny self-indulgence!